【摘要】 用 X射线光电子能谱对 MOCVD生长的未故意掺杂 Ga N单晶薄膜进行 N、 Ga组份测试 ,同时用 RBS/Channeling、 Hall测量和光致发光技术对样品进行结晶品质及光电性能研究 .结果表明 N含量相对低的 Ga N薄膜 ,其背景载流子浓度较高 ,离子束背散射沟道最小产额比 χmin较小 ,带边辐射复合跃迁较强 .在 N含量相对低的 Ga N薄膜中易形成 N空位 ,N空位是导致未故意掺杂的 Ga N单晶薄膜呈现 n型电导的主要原因 ;N空位本身对离子束沟道产额没有贡献 ,但它能弛豫 Ga N与 Al2 O3之间的晶格失配 ,改善生长的 Ga N薄膜的结晶品质更多还原

【Abstract】 The stoichiometry of GaN layers was determined using X-ray photoelectron spectroscopy (XPS),while the crystallinic qualities and optoelectronic properties were measured by Rutherford Backscattering (RBS) and ion channeling measurements,Van der Pauw Hall method and photoluminescence(PL),respectively.The results indicate that as the atom concentration in GaN layer decreases,background electron concentrations will increase but the value of χ min (the ion channeling minimum yield) decrease,at the same time,the intensity of the PL band edge emission become strong.The phenomena can be explained as follows,nitrogen vacancies are formed easily in the Ga-rich GaN films and the high background carrier concentration clearly results from a high concentration of the nitrogen vacancies;V N can relax the lattice mismatch between the sapphire substrate and as-grown GaN and can improve crystallinic qualities of the GaN films.更多还原